System and method for measuring advertising performance across multiple platforms

A method of measuring advertising performance on a computer network comprising:

• from a creative pixel associated with advertising content, receiving off-site data related to user activity on a third party website and a unique identifier associated with the user;
• from a site pixel associated with an advertiser's web page, receiving on-site data related to user activity on the advertiser's website and the unique identifier associated with the user;
• using the unique identifier associated with the user, associating a user's offsite activity on third party websites and on-site activity on the advertiser's website;
• and
• analyzing the on-site and off-site data to evaluate the performance of advertising content.

An advertising computer server system for use on a computer network comprising:

• a first software module providing a creative shell to a third party website on the computer network for publication of an advertisement, the creative shell including a creative shell pixel;
• a device graph database system providing an association between a user and a unique identifier for the user;
• a second software module to receive a request from the creative shell pixel for assignment of a unique identifier of a user and applying the device graph to assign the unique identifier to the user;
• and
• a third software module to receive a request from a site pixel embedded on an advertiser website to return the previously assigned unique identifier assigned to a user to the advertiser website, whereby a user activity on the third party website can be associated with subsequent user activity on the advertiser website.